This document describes the intrinsic muscles of the back. It divides the muscles into superficial, intermediate, and deep groups. The superficial muscles include the splenius capitis and cervicis which rotate the head. The intermediate muscles like the iliocostalis extend the vertebral column and head. The deep muscles such as the semispinalis and multifidus extend and rotate the vertebral column. The minor deep muscles like the interspinales and intertransversi stabilize the vertebral column.

1. Muscles of
Chest
Muscles of bac
k (INTRINSIC
)

2. •Superficial
•Splineus capitis
• Ligamentum nuchae and C7-T3T4
• Mastoid process and occipital bone
• Rotate the head same side
• Posterior rami of C3C4

3. •Splineus cervicis
Spinous process of T3-T6
Transverse process of C1-C3/C4
Rotate the head same side
Posterior rami of lower cervical
nerve

5. •Intermediate
• All three muscles have a common t
endenious origin from lumbar and l
ower thoracic vertebrae sacrum po
sterior Iliac crest sacroiliac and sup
raspinatus ligament

6. •Iliocostalis
• Costal angle of ribs and transvers
e process of cervical vertebrae
• Uniletraly flex and Bilateraly ext
end the verteral column and exten
d head
• Posterior rami of cervical nerve

7. •Longissimus
•Lower ribs transverse proce
ss of C7-T12 and mastoid p
rocess
•Same
•Same

8. •Spinalis
• C2 T1-T8 occipital bone of skull

9. •Deep
•Semispinalis
• Transverse process of C4'T10
• Spinous process of C2-C4
• Extend and Contraletray rotate the ver
tebral column and head
• Posterior rami of cervical nerve

10. •Multifidus
• Sacrum posterior Iliac spine common
tendenious of erector spinal mamillar
y process of lumbar transverse proces
s of T1-T3 articular process of C4-C7
• Spinous process of vertebrae
• Stabilise the vertebral column
• Posterior rami of spinal nerves

11. •Rotators
• Transverse process of vertebrae
• Lamina and spine of vertebrae ju
st above
• Stabilise the vertebral column
• Posterior rami of spinal nerves

12. • MINOR DEEP INTRINSIC MUSCLES
• Interspinales
• Spans between spines of vertebrae and stabilise the
vertebral column
• Intertransverseri
• Spans between transverse process of vertebrae and
stabilise vertebral column
• Levator costarum
• Transverse process of c7-T11
• Ribs just below
• Elevate the rib